Portable chemical oxygen generator

ABSTRACT

A portable chemical oxygen generator for delivering oxygen to a patient is described. The generator includes a housing containing a reaction chamber. Within the reaction chamber is a quantity of a peroxide adduct. A valve is provided with a lower portion of the valve in fluid communication with the reaction chamber. An upper portion of the valve is in fluid communication with a reservoir that holds a quantity of an aqueous solution. An internal chamber is formed within the valve by releasable seals that separate the internal chamber from the upper portion of the valve and a lower portion of the valve. The internal chamber holds a quantity of a peroxide-decomposing catalyst. The generator also includes a valve actuator. Operation of the valve actuator releases the seals in the valve and creates a fluid path from the reservoir through the internal chamber into the reaction chamber. When the valve is actuated, the aqueous solution flows from the reservoir through the internal chamber and into the reaction chamber. This flow washes the catalyst into the reaction chamber along with the aqueous solution. The solution and catalyst mix with the peroxide adduct and cause an oxygen-generating reaction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of and claims the benefit ofapplication Ser. No. 15/811,324 filed Nov. 13, 2017, which itself is acontinuation-in-part of application Ser. No. 15/366,891 filed Dec. 1,2016 (now U.S. Pat. No. 9,849,312), the entire disclosures of both ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The present application is generally directed to portable chemicaloxygen generators and, more particularly, to generators that are capableof producing high-purity oxygen in medical emergencies or othersituations in which a reliable and simple-to-operate system is needed.

COPYRIGHT NOTICE

A portion of the disclosure of this patent document contains materialsubject to copyright protection. The copyright owner has no objection tothe facsimile reproduction by anyone of the patent document or thepatent disclosure, as it appears in the Patent and Trademark Officepatent files or records, but otherwise reserves all copyrightswhatsoever.

BACKGROUND OF THE INVENTION

Without breath, life ceases. Oxygen—the second most abundant element inair—is essential for the numerous metabolic processes that sustain humanlife. While humans can survive without food for weeks and without waterfor days, survival is counted in minutes if the supply of oxygen ceases.And even if restored, brain damage may result if the oxygen deprivationwas too long; the severity increases with each passing minute.

Generally, sources of oxygen for treating acute medical conditions arenot readily available for members of the public to help a victim beforefirst responders arrive, and the attendant delay in administering oxygenbefore such trained help arrives may result in further injury or death.First responders typically arrive with an oxygen source, usually acompressed gas cylinder. Those oxygen cylinders are heavy, cumbersome,costly to transport, and potentially dangerous. For example, theDepartment of Veterans Affairs warns that an oxygen cylinder can beturned “into a missile” if a cylinder fractures, and the “[e]scaping gaswill propel the cylinder with enough force to penetrate cinder blockwalls.” Seehttp://www.patientsafety.va.gov/professionals/hazards/oxygen.asp. Use ofgas cylinders requires training to ensure safe and proper administrationof gas to a patient—members of the public, for the most part, lack suchknowledge.

Other devices for delivering oxygen include oxygen concentratormachines. These devices use electrically-powered mechanisms to separateoxygen from ambient air and deliver an oxygen-rich stream of gas to apatient. Shortcomings for these devices include the fact that they areoften quite heavy, require batteries or some other power source, and arenoisy. Thus, their use in emergent situations is limited to places wherepower is available, either to operate the device itself or to keepon-board batteries sufficiently charged. Additionally, as oxygenconcentrators depend on the quality of the ambient air, their use isnegatively affected in heavily polluted areas. Also, altitude affectsthe delivery of oxygen from these types of devices.

Another solution to the delivery of oxygen in emergent situations is achemical oxygen generator, which is a device that releases oxygen via achemical reaction. One example, sometimes called an “oxygen candle,”relies on the combustion of a chemical reaction to release oxygen. Theoxygen source is an inorganic superoxide, chlorate, or perchlorate mixedwith a combustion agent, such as iron. A firing pin ignites the mixture.And while such devices can deliver oxygen in an emergency, they operateat an extremely high temperature and are potentially a fire hazard. Toprotect surrounding structures, significant thermal insulation must beprovided.

Combustion-driven generators have been around for some time and arestill used, for example, in the airline and mining industries. Incommercial aircraft, this type of emergency oxygen is available topassengers to protect them from cabin pressure drops (the cockpit crewuses compressed oxygen canisters instead). Modern aircraft systemsgenerally use the decomposition of a mixture of chlorates, perchlorates,and sometimes superoxides that decompose exothermically above 400° C. toproduce oxygen and salt. Ignition using an explosive cap causes the drychemicals to react, resulting in oxygen production. While such systemscan reliably produce oxygen for periods of 15 minutes or longer, thestorage of explosive and flammable materials on board a commercialaircraft poses significant safety risks. And while the chemical mixturesin these devices can be stored almost indefinitely at both cold and hottemperatures, there have been real world tragedies. For example, on May11, 1996, accidental ignition of generators in the aircraft's cargo holdcaused the ValuJet Flight 592 crash. Ten years earlier, on Aug. 10,1986, an ATA DC-10 was destroyed while parked at O'Hare Airport due tothe accidental activation of an oxygen generator. And on Feb. 24, 1997,a fire broke out on the Russian Mir space station after a cosmonautignited an oxygen-producing perchlorate canister to supplement the spacestation's air supply.

SUMMARY OF THE INVENTION

Accordingly, there is a need for a chemical oxygen generation devicethat overcomes the deficiencies of known systems. Such a device would berelatively lightweight, not require pressurized gases, producehigh-purity oxygen for extended periods of time (e.g., up to 20minutes), and have a long shelf/storage life. Such a device would alsobe relatively simple to operate, so that the general public would beable to deliver oxygen in emergent situations before medical personnelarrive. Such a device would also enable the delivery of oxygen inaustere conditions (e.g., high altitude, military far-forward areas).Moreover, such a device is desirable in a number of non-criticalsettings, for example, at sporting events where oxygen-depleted athleteswould benefit from supplemental oxygen or in rural areas, where accessto other forms of supplemental oxygen may not be available.

The present invention overcomes these and other disadvantages of priorart systems and methods.

According to one embodiment of the invention, an oxygen generatorincludes a housing, a reaction chamber within the housing holding aperoxide adduct, and a valve. A lower portion of the valve is in fluidcommunication with the reaction chamber. The valve also includes aninternal chamber within the valve. The internal chamber is formed byreleasable seals separating the internal chamber from the upper portionof the valve and a lower portion of the valve. The internal chamberholds a peroxide-decomposing catalyst. A reservoir holding an aqueoussolution is in fluid communication with the upper portion of the valve.The generator also includes a valve actuator. Operation of the valveactuator releases the seals in the valve and creates a fluid path fromthe reservoir through the internal chamber into the reaction chamber.When the valve is actuated, the aqueous solution flows from thereservoir through the internal chamber, washing the catalyst into thereaction chamber. The aqueous solution and catalyst mix with theperoxide adduct, causing an oxygen-generating reaction.

According to other embodiments, operation of the valve releases theseals in the valve and creates (1) a first fluid pathway from thereservoir through the internal chamber into the reaction chamber,wherein the first fluid pathway is configured to: cause the aqueoussolution to flow from the reservoir through the internal chamber andcause the aqueous solution and catalyst to be transported into thereaction chamber and to react with the peroxide adduct, resulting in anoxygen-generating reaction; and (2) a second fluid pathway through theapproximate center of the valve, wherein the second fluid pathway isconfigured to allow oxygen generated by the oxygen-generating reactionto pass therethrough.

According to a further embodiment, when the valve is actuated an outletpath for the flow of oxygen generated by the reaction through the valveand out of the device is provided. According to another embodiment, theoutlet path is in fluid communication with the second fluid pathway, theoutlet pathway configured to allow oxygen generated by the reaction toflow out of the device.

According to a further embodiment, the oxygen generator includes aliquid impermeable, gas permeable membrane disposed in the outlet path.

According to a further embodiment, the valve actuator of the oxygengenerator includes a threaded, rotatable shaft and the valve includes athreaded valve portion engaged with the threaded rotatable shaft.Rotation of the shaft of the valve actuator causes displacement of thevalve, creating a fluid path through the valve. According to yet anotherembodiment, the valve actuator includes an actuation handle (e.g.,lever) external of the housing and connected with the shaft, whereinmovement of the handle causes rotation of the shaft to actuate thevalve.

According to a further embodiment, the oxygen generator includes a valvesupport assembly extending upward from the bottom of the housing forengagement with the valve; wherein the valve further comprises at leastone valve body tab, and wherein the valve is secured within the housingby engaging the at least one valve body tab with at least one slotformed in the valve support assembly.

According to a further embodiment, the oxygen generator includes one ormore sleeves located within the reaction chamber, wherein the peroxideadduct is located within the one or more sleeves. According to anotherembodiment, at least one of the one or more sleeves comprises aplurality of pouches. According to yet another embodiment, at least oneof the one or more sleeves is sealed at at least one intermediatelocation, creating a plurality of pouches.

According to a further embodiment, the oxygen generator includes atemperature stabilizing material in the reaction chamber along with theperoxide adduct. According to another embodiment, the temperaturestabilizing material includes one or more of a powder, a tablet, and acapsule. According to another embodiment, the temperature stabilizingmaterial may be combined with other compounds, including waxes, e.g.,paraffin. These other compounds may be mixed with the powder,incorporated within the tablets or capsules, or provide a coating forthe tablets or capsules. According to yet another embodiment, theperoxide adduct includes sodium percarbonate. According to a stillfurther embodiment, the aqueous solution includes water and ananti-freeze substance. According to a yet another embodiment, thecatalyst includes manganese dioxide.

According to a further embodiment, the oxygen generator includes a heatsink within the housing, wherein the heat sink comprises at least onecompartment filled with a liquid, solid, or combination thereof.

According to a further embodiment, the oxygen generator includes arestraint connected with the valve actuator, wherein actuation of thevalve occurs after overcoming the restraint.

According to a further embodiment, the oxygen generator includes acompartment configured to store a face mask or nasal cannula and hosing.According to another embodiment, the compartment is releasably attachedto the housing. According to yet another embodiment, the restraint isconnected with the compartment, wherein overcoming the restraintreleases at least a portion of the compartment from the housing.

According to a further embodiment, the housing of the oxygen generatorincludes an outer layer where the outer layer is separated from asurface of the housing.

According to a further embodiment, the housing of the oxygen generatorincludes a pressure relief mechanism.

According to a further embodiment, the oxygen generator includes acondensate trap disposed at an outflow portion of the outlet path.

According to a further embodiment, the valve of the oxygen generatorenters the reaction chamber from above after actuation. The reactantchamber is configured with a containment volume, the containment volumebeing the volume of the reactant chamber in a space below the valve. Thegenerator is configured so that the volume of the aqueous solution, thecatalyst, and the peroxide adduct is less than the containment volume.

According to one embodiment of the invention, a valve for use in anoxygen-generating apparatus comprises a rotatable actuator; wherein therotatable actuator comprises a threaded shaft, and wherein the threadedshaft includes a central bore and at least one opening in the threadedshaft; a valve body, wherein the valve body comprises a threaded innersurface, the threaded inner surface being engaged with the threadedshaft, the valve body being fix in rotation and linearly movable alongthe shaft from an unactuated position to an actuated position; a valvehousing, the valve housing comprising an inlet port, an outlet port, andan inner chamber portion located between the inlet port and the outletport; a plurality of releasable seals engage between an outer surface ofthe valve body and an inner surface of the valve housing when the valvebody is in the unactuated position, wherein a first and second seal forma liquid tight portion of the valve above and below the inlet port ofthe valve housing, wherein the second seal and a third seal form aliquid tight seal above and below the inner chamber portion of the valvehousing, and wherein, when rotation of the rotatable actuator causes thevalve body to move from the unactuated position to the actuatedposition, the plurality of seals are disengaged from between the valvebody and the valve housing.

According to one embodiment of the invention, a method for providing anactuator valve for a chemical oxygen generator comprises: providing anaqueous solution reservoir; providing a valve housing, the valve housinghaving a housing inner bore open at a proximal end and a housing sideopening distal of the proximal end, the aqueous reservoir sealed to thevalve housing, the housing side opening providing fluid communicationbetween the housing inner bore and an interior of the reservoir;providing a valve body having a body inner bore open at a proximal endand a body side opening between the body inner bore and an outer surfaceof the valve body, the body side opening being distal of the proximalend of the valve body; disposing the valve body within the bore of thevalve housing, wherein the valve body and valve housing form a firstreleasable seal between an outer surface of the valve body and the innersurface of the valve housing, the first releasable seal located distalof the housing side opening and the body side opening, wherein the bodyside opening is adjacent the housing side opening, wherein the valvebody and valve housing form a second releasable seal between the outersurface of the valve body and the inner surface of the valve housing,the second releasable seal located proximal of the housing side openingand forming an end of a catalyst chamber, wherein the valve body andvalve housing form an inlet path from the proximal end of the valvehousing and into the catalyst chamber, the inlet path located between anouter surface of the valve body and the inner surface of the valvehousing; positioning the valve body and valve housing so that theirproximal ends are above the reservoir; introducing an aqueous solutioninto the proximal open end of the valve body, wherein the solution flowsthrough the bore and body side opening of the valve body, through thehousing side opening, and into the aqueous solution reservoir;introducing a catalyst into the catalyst chamber along the inlet path;providing an end cap having an inner bore, the end cap including aproximal sealing structure and a distal sealing structure; inserting theend cap into the proximal ends of the valve housing and valve body, thedistal sealing structure forming a third seal between the inner bore ofthe valve body and an outer surface of the end cap and the proximalsealing structure forming a fourth releasable seal between an innersurface of the valve housing and the outer surface of the end cap.

According to one embodiment of the invention, a method of chemicallygenerating oxygen comprises: providing a housing; providing a fluidreservoir located within the housing; providing a reaction chamber inthe housing; providing an aqueous solution in the fluid reservoir;providing a peroxide adduct in the reaction chamber; providing a valvecomprising an internal chamber; providing a catalyst in the internalchamber; providing a valve actuator connected to the valve; actuatingthe valve actuator, which causes the aqueous solution and the catalystto be transported into the reaction chamber; generating oxygen inresponse to actuation of the valve actuator. According to anotherembodiment, actuation of the valve actuator comprises a rotationalmovement.

According to one embodiment of the invention, a method of chemicallygenerating oxygen comprises: providing an aqueous solution in a firstchamber; providing a catalyst in a second chamber; providing a peroxideadduct in a third chamber; and actuating an actuator to combine theperoxide adduct, aqueous solution, and catalyst, wherein oxygen isgenerated in response to the actuating step. According to anotherembodiment, actuation of the actuator consists of a single step.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated in the figures of the accompanyingdrawings, which are meant to be exemplary and not limiting, and in whichlike references are intended to refer to like or corresponding parts.

FIG. 1 depicts an exploded view of the oxygen delivery system of thepresent invention in the unactuated state.

FIG. 2A depicts a cross-sectional view of the oxygen delivery system ofthe present invention without any chemical reactants or water in thedevice.

FIG. 2B depicts a cross-sectional view of the oxygen delivery system ofthe present invention, with chemical reactants and water in the device,in the unactuated state.

FIG. 2C depicts a cross-sectional view of the oxygen delivery system ofthe present invention, with chemical reactants and water in the device,in the actuated state.

FIG. 3A depicts an exploded view of the valve assembly of the oxygendelivery system of the present invention.

FIG. 3B depicts a cross-sectional view of the valve assembly of theoxygen delivery system of the present invention in the unactuated state.

FIG. 3C depicts a cross-sectional view of the valve assembly of theoxygen delivery system of the present invention in the actuated state.

FIG. 3D depicts a cross-sectional view of the valve assembly of theoxygen delivery system of the present invention in the unactuated state.

FIG. 3E depicts a cross-sectional view of an embodiment of the oxygendelivery system of the present invention in which the valve and capseparate and drop from the valve body into the housing after actuation.

FIG. 3F depicts a cross-sectional view of an alternative embodiment ofthe valve assembly of the oxygen delivery system of the presentinvention in the unactuated state.

FIG. 3G depicts a cross-sectional view of the valve assembly of analternative embodiment the oxygen delivery system of the presentinvention in the actuated state.

FIG. 4A depicts a perspective view of the valve body of the oxygendelivery system of the present invention.

FIG. 4B depicts a side view of an alternative embodiment of the valvebody of the oxygen delivery system of the present invention.

FIG. 5A depicts the exit path for the generated oxygen in across-sectional view of the oxygen delivery system of the presentinvention.

FIG. 5B depicts an alternative embodiment of the exit path for thegenerated oxygen in a cross-sectional view of the oxygen delivery systemof the present invention.

FIG. 6A depicts a top view of the oxygen delivery system of the presentinvention and further depicts the actuation handle in the unactuatedstate.

FIG. 6B depicts a top view of the oxygen delivery system of the presentinvention and further depicts the actuation handle in the actuatedstate.

FIG. 6C depicts a perspective view of an alternative embodiment of theoxygen delivery system of the present invention and further depicts theactuation handle in the unactuated state.

FIG. 7 depicts a cross-sectional view of the ratchet on the device lidand the corresponding pawl on the underside of the actuation handle.

FIG. 8 depicts the top view of the interior of a water trap of thepresent invention and the flow path of gas through the trap.

FIG. 9 depicts the top view of the interior of an alternative embodimentof a water trap and the flow path of gas through the trap.

FIG. 10 depicts a partially assembled valve and reservoir according to afurther embodiment of the invention.

FIG. 11 depicts a perspective view of an alternative embodiment of theinterior of the housing of the oxygen delivery system of the presentinvention.

FIG. 12 depicts a side view of an alternative embodiment of the interiorof the housing of the oxygen delivery system of the present invention

FIG. 13 depicts a perspective view of an alternative embodiment of theinterior of the housing with the valve assembly of the oxygen deliverysystem of the present invention.

FIG. 14 depicts a sleeve comprising pouches containing anoxygen-generating mixture of the oxygen delivery system of the presentinvention.

FIG. 15 depicts a perspective view of an alternative embodiment of theinterior of the housing with sleeves comprising pouches containing anoxygen-generating mixture of the oxygen delivery system of the presentinvention.

FIG. 16 depicts a perspective view of the heat sink of the oxygendelivery system of the present invention.

FIG. 17 depicts a cross-sectional view of an alternative embodiment ofthe oxygen delivery system of the present invention, with chemicalreactants, heat sink, and water in the device, in the unactuated state.

FIG. 18 depicts a perspective view of an alternative embodiment of theinterior of the housing with the valve assembly of the oxygen deliverysystem of the present invention.

DETAILED DESCRIPTION

A portable oxygen generator and the method of making and using such agenerator according to embodiments of the present invention areprovided. As described below, the present invention discloses amechanism whereby a device containing an adduct chemical such as sodiumpercarbonate (“NaPerc”), which releases oxygen when mixed with water (orother liquids) in the presence of a suitable catalyst, e.g., manganesedioxide (“MnO₂”), is held in a dry state and separated from the catalystuntil such time as oxygen is required. An example of such a time is whenintervention in a respiratory-related medical emergency is required, atwhich point an operator will initiate the process detailed below.Because generating oxygen from such adducts is usually exothermic andusually required over an extended period of time, a reaction-moderatingchemical, for example, trisodium phosphate dodecahydrate (“TSP”), mayalso be provided. This moderating chemical is provided as tablets,capsules, or other agglomerations of certain dimensions mixed with theadduct chemical to facilitate release of the chemical over time. Othersustained-release forms are also within the scope of the invention.According to other embodiments, a heat sink is provided to moderate heatgenerated by the exothermic reaction.

A device according to an embodiment of the invention holds water 175 ina water reservoir 170, as shown in FIG. 2B. The water reservoir 170 isin fluid communication with a valve assembly 200. Within the valveassembly 200 is a chamber 265 that is provided to hold the catalyst 260.Below the valve assembly 200 and water reservoir 170 is a housing 140that holds an oxygen-generating mixture 190 that in an embodiment of theinvention is comprised of an adduct chemical 191 mixed with tablets,capsules, and/or powder formed of a moderating chemical 192. In anembodiment of the present invention, the capsules are water-solublecapsules. In another embodiment, the moderating chemical may be combinedwith other compounds, including waxes, e.g., paraffin. These othercompounds may be mixed with the powder, incorporated within the tabletsor capsules, or provide a coating for the tablets or capsules.

When the valve assembly 200 is actuated by rotation of a handle 180located at the top surface of the oxygen delivery system 100, water 175in the water reservoir 170 flows through the valve assembly 200,including through the chamber 265 holding the catalyst 260, and into thehousing 140 holding the adduct chemical 191 and moderator 192. Byflowing the water 175 through the chamber 265 holding the catalyst 260,the system 100 assures that the entire amount of the catalyst 260 willbe delivered to the housing 140 where the oxygen generation reactionwill take place. A restraint 189 (see FIG. 6A) between the handle 180and the lid 120 is removed so that the handle 180 may be activated. Inan embodiment of the present invention, the restraint 189 is a tape of astrength that will prevent accidental activation of this one-time-usedevice but not inhibit activation when generated oxygen is intended ordesired. It is important to note that an important purpose of thisinvention is to be widely available for use, not only in a number ofdifferent environments, but also by a number of different operators.Thus, it is a purpose of this invention, and it has been so designed, toallow for a variety of different operators. Accordingly, the actuationhandle 180 and the restraint 189 are designed to reduce as much aspossible the likelihood of accidental actuation of this single-use-onlydevice while at the same time allowing for operators of varyingstrength, physical condition, and the like to perform the relativelyuncomplicated two-step process of removing (or otherwise overcoming) therestraint 189 and turning the actuation handle 180 from the closed tofully open position, as described below. Consequently, the presentinvention has been designed for actuation for use by not onlyfully-abled adults, but also, for example, an older user with arthritisof the hand, wrist, shoulder, or elbow, or a young user incapable ofcomprehending and completing complicated tasks.

Once actuated, the valve assembly provides a path for oxygen generatedby the reaction to flow upward for delivery to a patient. The upwardflow of oxygen is illustrated in FIGS. 5A and 5B. For example, accordingto an embodiment illustrated by FIG. 5A, generated oxygen enters thevalve assembly 200 at the bottom and exits the valve assembly 200 abovethe water reservoir 170. According to an alternative embodimentillustrated by FIG. 5B generated oxygen enters valve assembly 200′ atthe bottom and exits the valve assembly 200′ above the water reservoir170. Oxygen flows into a space below a gas-permeable, liquid-impermeablemembrane 171 that is disposed above the water reservoir 170 but belowthe lid 120. The oxygen passes through the membrane 171 and into anoxygen-collecting chamber 122. The chamber 122 is coupled with an outletport 125. Oxygen can then be delivered to a patient by connecting a hoseto a facemask or nasal cannula (not shown).

In one embodiment of the invention, the device has a hose and facemask,or a hose and nasal cannula, that comes pre-connected with the oxygenport 125 on the device 100 so that when there is a need for oxygengeneration, the separate step of connecting a hose and facemask forpatient use is not necessary. In another embodiment of the invention,the pre-connected hose and facemask or nasal cannula (not shown) aresecured to the lid 120 by an attachment means (not shown). In anotherembodiment of the invention, the pre-connected hose and facemask ornasal cannula (not shown) are located within compartment 110 that isreleasably attached to housing 140 (see FIG. 6C). In another embodimentof the invention, the hose and facemask or nasal cannula on the lid 120(not shown) are not pre-connected with the device 100 at the oxygen port125, but are secured to the lid 120 by an attachment means (not shown).

The device 100 will now be discussed. FIG. 1 shows an exploded view ofan oxygen delivery system according to an embodiment of the invention.An oxygen delivery system 100 is comprised of a housing lid 120 fittedto a housing 140, which in the FIG. 1 embodiment is an open-faced box.Connected with, and situated between, the lid 120 and the housing 140 isthe valve assembly 200.

The lid 120 is designed to engage with the rim of the housing 140 tocreate a gas- and liquid-tight seal. A pressure relief valve (not shown)is provided to prevent damage to the device from internal pressure ifthe outlet port 125 becomes clogged or otherwise does not allow oxygento flow out. According to one embodiment, the maximum pressure aboveatmospheric pressure is between 0.1 and 40 psi, preferably between 0.8and 3 psi, and most preferably 1 psi. In one embodiment of theinvention, the pressure relief valve (not shown) is provided in the lid120.

According to the embodiment shown in FIG. 1, the peripheral region oflid 120 is raised, and the volume underneath that region is anoxygen-accumulation chamber 122. Oxygen port 125 connects with thechamber 122. The port 125 also provides an interface for deliveringgenerated oxygen to an individual in need.

The housing 140 may be square, rectangular, circular, or any other shapethat will provide sufficient volume to hold the reactant chemicals. Theshape of the housing 140 may also be irregular or otherwise shaped tofit within a storage space, such as a storage bay of a vehicle (e.g., anaircraft, ship, train, or the like). The housing 140 and/or the lid 120may include structures such as a handles (not shown) or straps to securethe device 100 in a storage space. The device 100 may also includeloops, buckles, and the like. The housing or lid may also includeplacards providing instructions for using the device. The housing or lidmay be colored to improve the device's visibility (e.g., emergencyorange), may include luminescent pigments, or may be painted orotherwise decorated in a manner that will facilitate the device's use inlow-light situations.

The interior surface 121 of housing lid 120 has a series of ribs 129extending downward to provide mechanical strength and, as discussedbelow, hold the upper surface of the water reservoir 170 and themembrane 171 (see FIG. 5A) away from the inner surface 121 of lid 120.This prevents the membrane 171 from adhering to the surface of the lid120 (e.g., were membrane 171 to become wet), which allows oxygengenerated by the device to flow through the chamber 122 to the port 125.

As shown in FIG. 2A, the interior of the housing 140 has walls 142 and abottom surface 143. A series of spaced-apart ribs 146 run vertically upthe walls 142 and along the bottom surface 143. The ribs 146 along thewall 142 extend vertically the same distance from the bottom surface 143and terminate to form shelves 148 that extend away from the wall 142.There are also a series of bottom-surface ribs 149 extending upward fromthe bottom surface 142. The ribs 146 and 149 also serve to providestructural strength to the housing 140 and may meet at the intersectionbetween the wall 142 and bottom surface 143. Alternative embodimentsthat do not include some or all of the aforementioned ribs arenevertheless within the scope of the present invention.

According to one embodiment, housing 140 is surrounded by an outer layer147 that allows for the transfer of heat out of the device and alsoprevents users from directly touching the surface of housing 140, whichmay become hot as a result of the oxygen-generating reaction. In oneembodiment, the outer layer 147 has a series of perforations to allowair to circulate across the surface of housing 140. According to anotherembodiment, outer layer 147 may be formed from a mesh. According to astill further embodiment, housing 140 may include heat-exchangingsurfaces such as fins to facilitate the transfer of heat away from theoxygen-generating reaction.

According to an embodiment of the invention as shown in FIG. 2A, a valvesupport assembly 144 extends upward from the bottom surface 143. Valvesupport assembly 144 couples with the valve assembly 200, as will beexplained below. As shown in FIGS. 2A-2C, support plate 160 sits on theshelves 148 of wall ribs 146 in the housing 140. The support plate 160has an aperture in its center that lines up with aperture 124 in thehousing lid 120 for insertion of the valve assembly 200. The supportplate 160 is designed to support water reservoir 170. According to oneembodiment, support plate 160 includes openings that reduce the weightof the device and reduce the amount of material required to manufacturethe support plate. According to a further embodiment, instead of supportplate 160, ribs 146 extend from wall 142 to provide support for thewater reservoir 170.

According to an embodiment of the invention as shown in FIG. 2B, beforethe device 100 is actuated, the water 175, catalyst 260, andoxygen-generating mixture 190 (comprised of adduct 191 and moderator192) are all separated. Specifically, water is in water reservoir 170,catalyst 260 is in catalyst chamber 265, and oxygen-generating mixture190 is in housing 140. According to alternative embodiments, before thedevice 100 is actuated, the water 175 and catalyst 260 are combined inthe reservoir 170. According to further alternative embodiments, beforethe device 100 is actuated, catalyst 260 is combined withoxygen-generating mixture 190. After the device is actuated, asexplained more fully below, the water 175, catalyst 260, andoxygen-generating mixture 190 will all be located within the housing140, forming a liquid or semi-liquid composition. As shown in FIG. 2C,the volume of the reactants fills a portion of the housing 140.According to another embodiment, the valve support assembly 144 andhousing 140 are configured so that when the device is placed on ahorizontal surface, the level of the reactants in the housing 140 isbelow the bottom of the valve assembly 200. This will prevent, or limit,the amount of liquid entrained in the flow of gas through the valveassembly. According to another embodiment of the invention, the size andshape of the housing 140 is also designed so that if the device wereplaced on its side (i.e., so the valve assembly 200 is positionedhorizontally) the level of reactants would remain below the location ofthe valve assembly 200, ensuring that reaction components are notentrained in the gas flow. In this regard, openings in the support plate160 allow reactants to flow through the plate, thus increasing thevolume of the housing below the level of the valve assembly that canhold the reactants in the event the device is tilted during use.According to another embodiment as shown in FIG. 15, oxygen-generatingmixture 190 is located within sleeves 193.

As shown in FIG. 2B, water reservoir 170 sealingly connects with flanges214 and 216 on the valve assembly (see also FIGS. 3A-D and 4) so thatthe interior of the water reservoir 170 is capable of being in fluidcommunication with the valve assembly.

As shown in FIG. 5A, located above the reservoir 170 is a gas-permeable,liquid-impermeable membrane 171. According to one embodiment of theinvention, the membrane is hydrophobic. According to another embodiment,the membrane 171 is formed from Tyvek® by DuPont of Wilmington, Del.Other suitable materials for membrane 171 include Gore-Tex® by W. L.Gore, as well as perforated and microperforated liquid-impermeablefilms.

As shown in FIG. 1, the upper rim of housing 140 includes pins 139 thatextend upward. The pins 139 engage with corresponding holes (not shown)in the lower rim of lid 120. Corresponding holes 137 in the edge of thewater reservoir 170 and holes 138 in the edge of membrane 171 (notshown) fit over the pins 139 in housing 140. When the lid 120 is fittedon the housing 140, the pins 139 fix the edges of the reservoir 170 andmembrane 171 to the rim of the housing 140. In an alternativeembodiment, a flange (not shown) on the periphery of water reservoir 170is heat-sealed to the rim of housing 140.

As shown in FIG. 1, the exterior surface of housing lid 120 is higher atthe edges and slopes downwardly toward the central region, creating theoxygen-accumulation chamber 122 at the periphery region of the lid 120.The reduced profile in the center of housing lid 120 allows for theactuation handle 180 to not extend above the profile of the device 100,which may prevent accidental actuation when oxygen is not needed, whichnonetheless renders the one-time-only device unavailable for a trueemergent situation. In an alternative embodiment, the handle 180 extendsabove the lid 120, so that when the device 100 is viewed from the sidethe handle 180 is the topmost structure.

A detailed description of the valve assembly 200, shown in FIGS. 3A-D,will now be provided. FIG. 3A is an exploded view of valve assembly 200.FIG. 3B is a cross-sectional view of valve assembly 200 before thedevice is actuated. FIG. 3C shows a cross-sectional view of valveassembly 200 when the device has been actuated. FIG. 3D is across-sectional rendering of valve assembly 200. As shown in FIG. 3A,valve assembly 200 is comprised of a valve body 210, valve 220, screw230, nut 240, and cap 250. As shown in FIG. 3B, the valve 220 ispositioned with the valve body 210.

As shown in FIG. 2A, valve assembly 200 is connected at its lower endwith valve support assembly 144. The bottom of valve body 210 sits atopvalve support assembly 144, which is located on and extends upward fromthe bottom surface 143 of housing 140. Valve support assembly 144includes two extensions 154 and 156 that interlockingly engage withvalve body tabs 215, snapping into slots 153 in valve support assembly144. As described later, the valve assembly 200 is secured at its top tolid 120.

The top of valve body 210 has exterior threading 217 to engage with nut240. As will be discussed below, a portion of valve body 210 extendsthrough the hole 124 in the lid 120, and the nut 240 engages thethreading 217 to affix valve assembly 200 to lid 120. The nut 240secures the valve body 210 to the lid 120, and the interlocks 215 securethe valve body 210 to the bottom of the housing 140. This arrangementprevents the lid 120 and housing 140 from separating, for example, wheninternal gas pressure is generated inside the device.

According to embodiments of the present invention, valve assembly 200′,via valve body 210′, engages with valve support assembly 144 to securethe two assemblies together for both efficient operation of the device100 as well as to provide additional structural support to the device.According to a preferred embodiment, valve body tabs 215 extend axiallyfrom valve body 210′. As illustrated by FIG. 4B, two pairs of tabs 215comprise a first valve body tab 215 a and a second valve body tab 215 bon a first side of valve body 210 a and a third valve body tab 215 c anda fourth valve body tab 215 d on a second side of valve body 210 b, thissecond side generally being located on the opposite side of valve body210′. First valve body tab 215 a is generally located above second valvebody tab 215 b, and the same relationship is true for third valve bodytab 215 c and fourth valve body tab 215 d. According to otherembodiments, first valve body tab 215 a/third valve body tab 215 c islocated above, but offset from second valve body tab 215 b/fourth valvebody tab 215 d (not shown). According to other embodiments, only asingle valve body tab 215 (e.g., valve body tab 215 a/215 c) on eachside 210 a, 210 b may be used. According to further embodiments, morethan two valve body tabs may be used on each valve body side 210 a and210 b. For example, instead of using a pair of tabs 215 a and 215 b,three or more valve body tabs may be located on the first side 210 a andthe second side 210 b of valve body 210′.

In a preferred embodiment, each of first valve body tab 215 a and secondvalve body tab 215 b is generally “L” shaped in that each has a firstportion directly attached to the side of valve body 210′ that extends ina generally perpendicular direction from the side of valve body 210′,and a second portion that extends in a direction parallel to the side ofvalve body 210′, as illustrated by FIG. 4B. The same is true for valvebody tabs 215 c and 215 d. In an alternative embodiment, valve body tabs215 a-d are not attached to valve body 210′, but rather areinjection-molded extensions from valve body 210′. According to otherembodiments, first valve body tab 215 a/third valve body tab 215 c andsecond valve body tab 215 b/fourth body valve tab 215 d take othershapes suitable for engaging with valve support assembly 144.

As previously discussed, valve support assembly 144 includes twoextensions 154 and 156. Slots (e.g., fitted engagements) are located oneach extension 154 and 156. According to embodiments, extension 154includes two indentations that each have a shape generally complementaryto that of the first pair of valve body tabs 215 a, 215 b. Theseindentations recess from a first face of extension 154, as illustratedby FIGS. 11 and 12. Similarly, extension 156 includes twoindentations—which likewise recess from a first face of extension156—with a shape complementary to that of the second pair of valve bodytabs 215 c, 215 d, as illustrated by FIG. 11. According to theseembodiments, the first face of extension 154 is opposite the first faceof extension 156, facilitating engagement of the valve body 210′ withthe valve support assembly 144.

As illustrated by FIG. 13 and further to the above, the securing ofvalve body 210′ to valve support assembly 144 is accomplished byaligning first valve body tab 215 a/third valve body tab 215 c andsecond valve body tab 215 b/fourth valve body tab 215 d with the indentsformed in valve support assembly 144. Once aligned, valve body 210′ ismaneuvered (e.g., turned or twisted) so that first valve body tab 215a/third valve body tab 215 c and second valve body tab 215 b/fourthvalve body tab 215 d engage with the corresponding indentations inextensions 154 and 156. The maneuvering of valve body 210′ continuesuntil first valve body tab 215 a/third valve body tab 215 c and secondvalve body tab 215 b/fourth valve body tab 215 d are prevented fromfurther maneuvering because the aforementioned tabs have abutted theends of the indentation channels. In one embodiment, first valve bodytab 215 a/third valve body tab 215 c and second valve body tab 215b/fourth valve body tab 215 d are located completely within theindentations in extensions 154 and 156. In another embodiment, at leasta portion of first valve body tab 215 a/third valve body tab 215 c andsecond valve body tab 215 b/fourth valve body tab 215 d are locatedwithin the indentations in extensions 154 and 156.

According to embodiments, valve body 210′ further includes protrusions221, as illustrated by FIG. 4B. According to a preferred embodiment, afirst protrusion 221 a is located generally equidistant from first valvebody tab 215 a and second valve body tab 215 b on the first side 210 aand the third valve body tab 215 c and fourth valve body tab 215 d onthe second side 210 b, and a second protrusion 221 b (not shown) islocated generally opposite first protrusion 221 a. Protrusions 221 aresized and shaped such that they prevent valve assembly 200′ from beingplaced into valve support assembly 144 at an inappropriate angle. Thesefeatures not only allow for valve assembly 200′ to be easily and quicklyengaged and disengaged from valve support assembly 144, but also provideadditional structural stability and support to the chemical oxygengenerator device of the present invention.

As shown in FIG. 4, which is a detailed view of valve body 210, sealingflanges 212, 214, 216 extend radially from the exterior of valve body210. When the device 100 is assembled, first sealing flange 212 engagesits upper surface against membrane 171. According to one embodiment, asshown in FIG. 5A, membrane 171 is trapped between the upper surface offlange 212 and a receiving surface on the bottom surface of lid 120.

The second sealing flange 214 and third sealing flange 216 are sealinglyconnected with upper and lower surfaces, respectively, of reservoir 170.The valve body 210 includes openings 218 and 219, on opposite sides ofthe valve body 210 between the second sealing surface 214 and the thirdsealing surface 216. Openings 218 and 219 allow water to enter into theinterior space of valve body 210 and flow into the housing 140 when theoxygen-generation operation is actuated.

According to an embodiment of the invention as shown in FIG. 3A, valve220 is located between screw 230 on the top and cap 250 on the bottom.Valve 220 and cap 250 are connected and move together, as an integralunit. Valve 220 is generally cylindrical in shape, although the diameterin its top half is narrower than the bottom. Valve 220 has two apertures228 and 229 that are opposite each other in the valve's side walls. Asshown in FIG. 3D, these apertures are positioned adjacent apertures 218and 219 of the valve body 210. As detailed below, apertures 228 and 229allow water from water reservoir 175 to pass through to the interior ofthe valve housing 210 when the device is actuated. Also, as shown inFIGS. 3B and 3C, openings 211 and 213 are provided in the valve housing210 between flanges 212 and 214. As will be discussed below, when thedevice is actuated, openings 211 and 213 allow generated oxygen to flowout of the valve 200.

The upper portion of the interior of valve 220 is threaded. The threadsof valve 220 engage threads on the outer surface of screw 230. The topportion of screw 230 rests in a groove at the top of valve body 210 andis captive below a shoulder of nut 240. Thus, screw 230 is fixed in thevertical direction with respect to the valve assembly 200. When thedevice is actuated, screw 230 rotates. The engagement of the threads ofvalve 220 with the screw 230 cause the valve 220 to travel downwardlyalong the threads of screw 230, resulting in a short downward verticaldisplacement by valve 220 with respect to the valve body 210. FIG. 3Cshows the valve assembly 200 after screw 230 has rotated to displacevalve 220 with respect to valve body 210.

Cap 250 is sized and configured for insertion into the interior of thebottom of valve 220. As shown in FIG. 3A, cap 250 has two vertical posts254, 256 that are integral with the rim at the top of cap 250; each post254, 256 has a snap engagement at the respective top end. As shown inFIG. 3D, when the cap 250 is inserted into the valve 220, these snapengagements atop posts 254, 256 interlock with the lower edges ofopenings 228 and 229, respectively. Once so engaged, valve 220 and cap250 are essentially a single unit that, as detailed below, move andoperate together inside the valve body.

Valve assembly 200 functions to provide gas- and liquid-tight sealsbetween regions of the device so that components of theoxygen-generating device are held separately until such time as oxygenis required and so that the interior of the device is protected fromexposure to the outside environment when the device is in the unactuatedstate. As shown in FIGS. 3B-D, o-rings located in slots formed on thevalve body 210, valve 220, screw 230, and cap 250 provide these seals. Afirst o-ring is held in slot 280, formed about the circumference of thehead of screw 230. This o-ring is seated between the top of screw 230and the interior of the valve body 210 to prevent generated oxygen fromexiting the housing lid 120 and also to prevent outside air—andespecially outside moisture—from entering the device during storage.

A second o-ring is held in slot 282 on the outside surface of valve body210. This o-ring is seated between valve body 210 and the edge ofopening 124 of housing lid 120 to both prevent generated oxygen fromescaping through opening 124 and seal the interior of the device fromoutside gas and moisture.

A third o-ring is held in slot 284 on the outer surface of screw 230.This o-ring is seated between screw 230 and the interior of valve 220 toboth prevent generated gas from escaping through the interior of thevalve assembly 200 and prevent water 175 from leaking out of reservoir170 through the interior of valve 220 when the device 100 is in theunactuated state.

A fourth o-ring is held in slot 286, formed on the surface of valve 220.This o-ring is seated between valve 220 and the interior of valve body210 above openings 218, 219, 228, and 229 to prevent water 175 fromleaking out of reservoir 170 when the device 100 is in the unactuatedstate.

A fifth o-ring is held in slot 288, formed in the surface of valve 220.This o-ring is seated between valve 220 and valve body 210, belowopenings 218, 219, 228, and 229, and below flange 216. This o-ringprevents water 175 from traveling through the valve assembly 200 whenthe device is in its unactuated state. This o-ring also forms a sealabove catalyst chamber 265 and keeps the catalyst 260 separated from thewater 175 when the device is in the unactuated state.

A sixth o-ring is held in slot 290, formed on the outer surface of cap250. This o-ring is seated between cap 250 and the interior of valve 220and isolates the catalyst 260 from the interior of the valve 220.

A seventh o-ring is held in slot 292, formed on the outer surface of thecap 250. This o-ring is seated between cap 250 and the interior of valvebody 210 and seals the catalyst 260 and catalyst chamber 265 from thehousing 140 when the device is in the unactuated state.

FIG. 3C shows the valve assembly 200 in its actuated state after screw230 has rotated, driving valve 220 downward with respect to valve body210. The o-ring in slot 280 maintains a seal between screw 230 and valvebody 210. Likewise, the o-ring in slot 282 maintains a seal with lid120. As a result, gas generated in the housing 140 is prevented fromescaping through the opening 124 in lid 120 and, instead, flows intochamber 122 and exits from the oxygen port 125.

According to alternative embodiments, valve assembly 200′ allows foroxygen generated in the reaction chamber within housing 140 to travelthrough a pathway in the interior of valve assembly 200′ rather thanalong the same pathway by which water and catalyst are introduced intohousing 140. This interior pathway allows for generated oxygen to flowupward through the interior of valve assembly 200′, unimpeded by thedownward flow of reactants, and out of valve assembly 200′ via openings211′ and 213′ provided in valve housing 210′, as illustrated in FIGS. 3Gand 5B. This interior pathway is an alternative to that depicted in FIG.5A. In a preferred embodiment, the interior pathway runs through theapproximate center of valve assembly 200′.

According to a preferred embodiment, valve assembly 200′ includes cap250′, which has pathway entrance hole 251′ in the cap's approximatecenter. FIG. 3F depicts a cross-sectional view of valve assembly 200′ ofthe oxygen delivery system 100 of the present invention in theunactuated state. Hole 251′ provides a pathway into a central bore 233′of screw 230′. The top of central bore 233′ includes openings 234′ and235′, which are located in screw 230′ at a location above slot 286′(which is the recess for the fourth o-ring). Once device 100 has beenactuated, gas exit pathways are created between openings 235′ and 211′and openings 234′ and 213′, as illustrated by FIG. 3G, which depicts across-sectional view of valve assembly 200′ of the oxygen deliverysystem of the present invention in the actuated state.

According to further embodiments, valve assembly 200′ allows for oxygengenerated in the reaction chamber within housing 140 to travel throughother interior pathways in valve assembly 200′. For example, cap 250′may include pathway(s) along its interior wall so that oxygen generatedin the reaction chamber flows along the sides of screw 230′ (i.e., alongthe threads of screw 230′ and valve body 210′). Other pathways withinvalve assembly 200′ are within the scope of the present invention.

Displacement of the valve 220 during actuation disengages both theo-rings in slots 284, 286, and 288 from between the valve 220 and valvebody 210 (or valve body 210′) and the o-ring in slot 292 from betweenthe cap 250 (or cap 250′) and the interior of valve body 210 (or valvebody 210′).

As shown in FIG. 1, the valve assembly 200 (or valve assembly 200′) isconnected at its top end with the circular opening 124 of the housinglid 120. The valve body's threaded end 217 is inserted through opening124. Nut 240 engages the threaded end, pulling the upper end of thevalve assembly against the lower surface of the lid 120. Handle 180 isconnected with the top of screw 230 of the valve assembly 200. Handle180 has an aperture 182 in its center that allows the handle 180 to beconnected with the valve assembly 200 by a screw 188 that is insertedthrough the aperture 182 into a threaded aperture 231 in the top ofscrew 230. According to one embodiment, ribs 232 on the inside surfaceat the top of screw 230 engage with corresponding ribs on a projectionon the lower side of the handle 180 (not shown) to communicaterotational force from the handle 180 to the screw 230.

As shown in FIG. 1, there is a circular ratchet 185 that is concentricwith, but outside of, circular opening 124. As shown in FIG. 7, ratchet185 is comprised of a plurality of spaced-apart individual teeth 186.FIG. 7 also shows a detailed view of the ratchet 185 and handle 180. Theratchet 185 is sized to be concentric with, but have a diameter lessthan, the handle 180. The ratchet is further sized so that theindividual teeth will engage with a pawl 184 on the underside of thehandle 180. The pawl 184 and teeth 186 are configured such that the pawl184 engages and passes each individual tooth 186 when traveling in onedirection, e.g., clockwise, but that once the pawl 184 passes a tooth186 the pawl 184 may not be reversed, e.g., travel counterclockwise pastthe tooth 186 just engaged. In the present invention, this configurationensures that once the oxygen generation process begins by actuating thehandle 180, there is no reversing the handle 180 or the process. This iscritical insofar as the device is single-use only, and an observer willbe able to ascertain quickly whether the device 100 of the presentinvention has been used or is available.

The arrangement and selection of chemical reactants in the device whenit is in its unactuated state, according to one embodiment, will now bedescribed. The reactant components are held in separate compartments,sealed from one another and from the outside environment when the deviceis in the unactuated state.

As shown in FIG. 2B, water 175 is held in water reservoir 170. Thereservoir 170, according to one embodiment, is made of a flexible,water-impermeable material such as silicon, low density polyethylene,polypropylene, aluminum, polycarbonate, or the like. According to oneembodiment, when the device is actuated, the reservoir collapses aswater drains out of it. The reservoir 170 surrounds the valve assembly200 and is sealed with flanges 214 and 216 of the valve assembly 200, asdiscussed above. The flexible reservoir is supported by plate 160. Thereservoir 170 is in liquid communication with openings 218 and 219 ofthe valve assembly. In the unactuated state, the water 175 is preventedfrom flowing through the valve assembly 200.

Within the valve assembly, catalyst chamber 265 holds the catalyst 260,which is sealed within that chamber by o-rings in slots 288 and 292. Thecatalyst 260 is selected from a variety of peroxide-decomposingcatalysts, including metal oxides, e.g., oxides of aluminum, cobalt,iron, platinum, titanium, and silver. Preferably, the catalyst 260 ispowdered manganese dioxide (“MnO₂”) with particle size of the MnO₂ beingpreferably between about a diameter of 5 μm and about 500 μm. Accordingto another embodiment, the catalyst 260 is activated MnO₂, i.e., MnO₂that has been subjected to a series of heat/oxygen/inert gas treatmentsthat skilled artisans use to produce an MnO₂ powder that is especiallyactive as a peroxide-decomposing catalyst 260.

The MnO₂ is provided in an amount effective to catalyze thedecomposition of hydrogen peroxide and produce the desired volume of O₂with regard to the types and amounts of the other reaction compounds.The amount of MnO₂ used in the composition also depends on the mesh sizeof the MnO₂ and on the degree of activation of the MnO₂. Such activatedMnO₂ powders are also very active in the decomposition of hydrogenperoxide, and while activated MnO₂ powders can be used in thecompositions of the disclosure, their use is not required.

Below the valve assembly 200 in housing 140 is the oxygen-generatingmixture 190, comprising a hydrogen peroxide adduct 191 and atemperature-stabilizing material 192. According to an embodiment,oxygen-generating mixture 190 is merely placed within housing 140.According to another embodiment, oxygen-generating mixture 190 islocated within pouches located in housing 140.

The amounts of water 175, oxygen-generating mixture 190, and catalyst260 are selected to achieve a desired rate and amount of oxygengenerated to provide adequate amounts of gas for a particular purpose,for example, to administer oxygen to a patient in respiratory distress.As discussed above, the size and shape of the housing 140 is selected sothat the total volume of the mixture will not contact the lower end ofthe valve assembly 200 when the device is in its normal, horizontalorientation. The amount of reactants and the size of the housing arealso selected so that should the physical orientation of the devicechange, e.g., the device being turned on its side so that the exteriorsurface of the bottom of housing 140 is no longer the surface had beenplaced on for actuation, the reactant mixture will not reach the valveassembly 200.

The hydrogen peroxide adduct 191 is a compound that will react withwater to generate hydrogen peroxide. This hydrogen peroxide thendecomposes to oxygen and water when it interacts with the catalyst 260.Suitable compounds may be adducts of hydrogen peroxide, including sodiumcarbonate and hydrogen peroxide, urea and hydrogen peroxide, and thelike. According to a preferred embodiment, the adduct 191 is sodiumcarbonate and hydrogen peroxide. According to a most preferredembodiment, the adduct 191 is NaPerc, an adduct of sodium carbonate andhydrogen peroxide with an empirical formula Na₂CO₃-1.4H₂O₂.

The temperature-stabilizing material 192 dissolves endothermically inwater. Preferably, such an agent has a heat of dissolution selected tolimit the temperature of the oxygen-generating reactions below asuitable maximum temperature. Suitable temperature stabilizing materialsinclude, for example, trisodium phosphate dodecahydrate, sodiumtetraborate decahydrate, disodium phosphate heptahydrate, disodiumphosphate dodecahydrate, and combinations of the foregoing. According toa preferred embodiment, the cooling agent is trisodium phosphatedodecahydrate (“TSP”) having the formula Na₂PO₄-12H₂O and a coolingcapacity of 40.25 cal/g.

The rate of dissolution of TSP, and hence the amount of cooling in thereaction, has been found to be affected by the TSP form. The reactionprofile of TSP powder and small TSP tablets differs, and thus TSP can beused as a powder, a tablet, a capsule, or combinations thereof, with theform selected being based on the desired reaction profile. For example,TSP powder dissolves more quickly than TSP tablets, resulting in morerobust cooling of an exothermic reaction; the oxygen-generating reactionaccording the present invention being an example. In some embodiments,TSP is used as a tablet and/or a capsule, either alone or in combinationwith TSP powder. According to a preferred embodiment, TSP tablets with adiameter of about 0.63 cm to about 0.97 cm and a thickness of about 0.31cm to about 0.50 cm are used. The TSP tablet faces may have flat orslightly outwardly curved profiles. According to yet another embodiment,the powder, tablets, or capsules may include other compounds, such aswaxes, e.g., paraffin, which may also affect the rate of dissolution.

According to embodiments, oxygen-generating mixture 190 is locatedwithin one or more compartments. According to a preferred embodiment,the one or more compartments are one or more sleeves 193. In anembodiment, oxygen-generating mixture 190 comprises a hydrogen peroxideadduct 191 and a temperature-stabilizing material 192. In a preferredembodiment, oxygen-generating mixture 190 comprises a hydrogen peroxideadduct 191 only. In a more preferred embodiment, the adduct 191 issodium carbonate and hydrogen peroxide. According to a most preferredembodiment, the adduct 191 is NaPerc, an adduct of sodium carbonate andhydrogen peroxide with an empirical formula Na₂CO₃-1.4H₂O₂.

Each sleeve 193 comprises a material that allows for penetration byliquid and other reactants. The sleeve 193 may, according toembodiments, take a variety of shapes, e.g., rectangular, circular, orcylindrical. The sleeve 193 material has sufficient liquid- andgas-permeability so as to minimally impede water 175 and catalyst 260from contacting oxygen-generating mixture 190 when the former areintroduced into housing 140. According to preferred embodiments, sleeve193 is comprised of a woven material with apertures sized such that whenthe device is (a) in the unactuated state, oxygen-generating mixture 190does not escape from the interior of sleeve 193 and (b) in the actuatedstate, water 175 and catalyst 260 may pass through the woven materialinto the interior of sleeve 193 to react with oxygen-generating mixture190. For example, according a preferred embodiment, theoxygen-generating reaction is possible because the mean particlediameter of oxygen-generating mixture 190 is between approximately500-900 microns, the mean particle diameter of catalyst 260 is less thanapproximately 50 microns, and the apertures of sleeve 193 are of adiameter size therebetween.

According to preferred embodiments, after being filled withoxygen-generating mixture 190, sleeves 193 are sealed (e.g.,heat-sealed) or clamped at junctions 197, creating a plurality ofindividually sealed pouches 195. For example, according to theembodiment illustrated in FIG. 14, sleeves 193 are sealed at twojunctions 197, resulting in three pouches 195. According to otherembodiments, sleeves 193 are sealed at one junction 197, resulting intwo pouches 195. According to further embodiments, sleeves 193 aresealed at three or more junctions 197, resulting in four or more pouches195.

The material used to make sleeves 193 is selected from materials that donot meaningfully inhibit or impede water and the catalyst beingtransported through the sleeve 193 to interact with theoxygen-generating mixture 190 contained therein. Additionally, thematerial used for sleeves 193 is selected from those susceptible ofbeing easily clamped and/or heat-sealed. Also, the material used to makesleeves 193 satisfies environmental, temperature, and other requirementsfor such oxygen delivery devices. By way of example, sleeves 193 may bemade of mesh/woven polyester or mesh/woven polypropylene.

According to further embodiments, sleeves 193 are made of a liquidsoluble material. According to these embodiments, sleeves 193 dissolvewhen contacted by water 175 and catalyst 260, which allowsoxygen-generating mixture 190 to mix with water 175 and catalyst 260.Thus, according to these embodiments, sleeves 193 may be made from amaterial without apertures.

According to the embodiment illustrated in FIG. 15, three sleeves 193,each comprising three pouches 195, are positioned within the bottom ofhousing 140. The three pouches 193 are designed to fit within housing140, and according to a preferred embodiment sleeves 193 are designed tobe conformable to the shape of housing 140. For example, sleeves 193Aflank sleeve 193B. Sleeve 193B is comprised of three pouches 195 ofconsistent dimension (e.g., squares or rectangles). Sleeves 193A eachinclude a first pouch and a third pouch designed to be conformable, oninstallation, with the curved portion of the interior wall of housing140. In an alternative embodiment, the first and third pouches of sleeve193A are preformed to be of the curved shape of the interior wall ofhousing 140. This configuration is designed to distributeoxygen-generating mixture 190 on the floor of housing 140 in anapproximately even fashion, regardless of the orientation of housing 140during transport, storage, or operation. According to furtherembodiments, oxygen-generating mixture 190 may be approximately evenlydistributed in housing 140 by other means, including, oxygen-generatingmixture 190 being contained within a single compartment or confinedunder a mesh material located adjacent the floor of housing 140.

Sleeves 193, once filled with oxygen-generating mixture 190, may befixed to the bottom of housing 140 by various fastening means, e.g.,screws threaded through sleeve 193 into corresponding apertures locatedin the bottom of housing 140 (not shown) or gluing. Alternatively,sleeves 193 may be fitted to the bottom of housing 140 by physicalcompaction.

As previously discussed, the oxygen-generating reaction of the presentinvention is exothermic. Recognizing that heat coming through thehousing may be undesirable for a manually handled device, a heat sink isplaced within housing 140. According to an embodiment, heat-sink 400includes base layer 401 and top layer 403, which includes compartments405 filled with a heat-absorbing substance.

According to a preferred embodiment, base layer 401 is a porous meshshaped to conform generally to the perimeter of the inner walls ofhousing 140, as illustrated by FIG. 16. Top layer 403, which includescompartments 405, is located above and secured to the top of base layer401. Top layer 403 has a shape similar to, though with an area generallyless than, that of base layer 401, as further illustrated by FIG. 16.

Top layer 403, according to a preferred embodiment, is generally planar(with the exception of compartments 405). Base layer 401 and top layer403 may be made from a material capable of providing structural supportfor compartments 405. For example, base layer 401 and top layer 403 maybe made from a polymer (e.g., polylactic acid).

According to embodiments, compartments 405 are filled with a liquid,solid, or combination thereof capable of absorbing a sufficient quantityof the heat generated by the oxygen-generating reaction of theinvention. According to a preferred embodiment, illustrated in FIG. 16,compartments 405 are sealed, liquid-filled pouches or bags holdingapproximately 250 ml of water each. In this embodiment, the 500 ml ofwater contained in compartments 405 absorbs heat generated by theoxygen-generating, exothermic reaction, thereby reducing thetemperatures of the exterior of housing 140 and outer layer 147 duringthe reaction of the invention. Additionally, similar totemperature-stabilizing material 192, heat sink 400 limits thetemperature of the oxygen-generating reactions below a suitable maximum.According to other embodiments, additional or fewer compartments 405, aswell as additional or less water in any or all compartments, may beincluded. According to yet further embodiments, a single U-shapedcompartment 405 may be included.

According to further embodiments, compartment(s) 405 alone, without theadded structure of top layer 403 and base layer 401, may function as theheat sink. In these embodiments, compartments 405 may sit on top ofsleeves 193 (or oxygen-generating mixture 190) in the reaction chamber.

As further illustrated by FIG. 16, base layer 401 and a top layer 403each include apertures 407 for allowing extensions 154 and 156 to passpartially therethrough. According to this configuration, and asillustrated in FIG. 17, heat sink 400 may be located in housing 140between valve assembly 200′ and sleeves 193.

Heat sink 400 is supported within housing 140 by posts 150, asillustrated by FIGS. 17 and 18. Posts 150 extend vertically from thebottom of housing 140. According to embodiments, posts 150 arepositioned to correspond with orientation holes 409 in heat sink 400.According to further embodiments, each post 150 may have at its distalend an aperture 151 for securing the heat sink 400 to the respectivepost 150 by use of a fastening element (e.g., screw, rivet, or thelike). In one such embodiment, a screw (not shown) may be threadinglyengaged with a corresponding post 150 via the aperture 151 in therespective post's distal end. In this embodiment, each orientation hole409 of heat sink 400 is aligned with a corresponding post 150 withinhousing 140 so that the aperture 151 of the respective post 150 may bealigned with the corresponding orientation hole 409 (as illustrated byFIG. 16) to permit a fastening element to be inserted therethrough, thusensuring a secure engagement of heat sink 400.

According to a preferred embodiment, as illustrated by FIGS. 17 and 18,each post 150 may include axially extending flanges 152. The portion offlanges 152 adjacent the aperture at the distal end of each post 150acts as a shelf providing additional structural support to heat sink400.

Additionally, heat sink 400 may serve as an alternative means fordissipating the heat generated when device 100 is actuated. For example,according to embodiments, heat sink 400 serves as a substitute fortemperature-stabilizing material 192. Thus, according to an embodiment,device 100 includes heat sink 400, but not temperature-stabilizingmaterial 192. In a preferred embodiment incorporating heat sink 400, thetemperature inside the device after actuation preferably remains below100° C., more preferably below 80° C., and most preferably below about50° C. In this preferred embodiment, the temperatures of the outersurface of the device after actuation preferably remains below 48° C.,and more preferably below 45° C.

As discussed earlier, this disclosure relates to a portable chemicaloxygen generator. The oxygen generated is the result of a chemicalprocess involving the combination of several chemical components orseveral chemical and mechanical components. By storing the components ofthe oxygen-generating reaction in separate, sealed compartments, and byprotecting those components from environmental moisture, the device canbe stored in the unactuated state for long periods of time, preferablylonger than one month, one year, two years, and three years at 10° C. to27° C.

Because the rate of reaction is controlled by adjusting the rate ofdissolution of the temperature-stabilizing material 192 (or by theabsorption of heat via heat sink 400), the maximum temperature of thedevice during operation can be controlled to remain preferably below100° C., more preferably below 80° C., and most preferably below about50° C. Also, by selecting reaction components according to an embodimentof the invention, oxygen can be produced in emergent situations withouttoxic by-products or volatile organic compounds—the result being thesecompositions generating high-purity, breathable oxygen.

One aspect of the disclosure is to an oxygen-generating compositionincluding NaPerc, MnO₂, TSP, and water. In an alternative embodiment,the water in the composition may also include antifreeze, e.g.,polyethylene glycol. In additional alternative embodiments, liquids ormaterials other than water that are capable of releasing peroxide fromthe peroxide adduct may be used in the composition.

Another aspect of the invention is a method of generating breathableoxygen that includes bringing an oxygen-generating composition of thedisclosure into contact with water. According to one embodiment of theinvention, the device generates oxygen that qualifies for labeling as“Oxygen, USP”—meaning that the generated oxygen meets the United StatesPharmacopoeia standard. The amount of water 175, catalyst 260, adduct191, and the amount and physical configuration of thetemperature-stabilizing material 192 can be selected such that oxygen isgenerated at a rate of at least 1 L/min, at least 2 L/min, at least 3L/min, at least 4 L/min, or at least 6 L/min for periods of 15 minutes,20 minutes, 30 minutes, 45 minutes, or 90 minutes (calculated based on90 L volume). Further, the oxygen-generating composition of thedisclosure can be prepared such that one or more of foam, toxicby-products, and volatile organic contaminants are minimized when thedevice is actuated. According to one embodiment of the invention, theoxygen generated by the device meets the Environmental ProtectionAgency's air quality standards for levels of VOCs (i.e., VolatileOrganic Compounds) present.

The disclosure further provides a method of generating oxygen includingcontacting an oxygen-generating composition of the disclosure withwater. As used here, “contacting” can include any of flowing the waterpast/through/into the oxygen-generating composition or immersing theoxygen-generating composition in the water. In some embodiments, thecontacting will occur by opening a valve in an upper compartmentcontaining water and a lower compartment containing theoxygen-generating composition and allowing gravity to drain the waterinto the lower compartment to initiate the reaction and release ofoxygen. The relative amounts of NaPerc, MnO₂, and TSP used in the methodof generating oxygen can be any amounts disclosed here for theoxygen-generating composition.

On contact with the water, the NaPerc adduct 191 decomposes to producesodium carbonate and hydrogen peroxide. The hydrogen peroxide furtherdecomposes to water and oxygen upon contact with the MnO₂, i.e.,catalyst 260. The decomposition rate of hydrogen peroxide depends on theconcentration of the hydrogen peroxide and on the reaction temperature.In various embodiments, the MnO₂ present is in an excess to overwhelmthe hydrogen peroxide with an abundance of catalyst 260. In someembodiments, an amount of MnO₂ provided in the range of about 0.3% toabout 1% of the weight of NaPerc adduct 191 is sufficient to react theH₂O₂ produced at a substantially instantaneous rate such that H₂O₂ isdecomposed to oxygen as quickly as the H₂O₂ is released from thedecomposition of NaPerc adduct 191. In such embodiments, the rate ofproduction of oxygen is substantially equivalent to the rate ofdecomposition of the NaPerc adduct 191 and the concentration of H₂O₂ inthe aqueous phase of the reaction remains at all times at exceedinglylow concentrations. For this reason, the exiting oxygen stream is alsosubstantially free of H₂O₂.

In a preferred embodiment of the present invention, water flows from anupper sealed compartment through a catalyst chamber 265 in valve 220,mixing with the catalyst 260 and exiting the valve assembly 210 as anaqueous-MnO₂ catalyst combination, whereupon it contacts the NaPercadduct 191 and TSP cooling agent 192 that are pre-located in the housing140. The NaPerc adduct 191 decomposes to produce sodium carbonate andhydrogen peroxide, with the hydrogen peroxide further decomposing towater and oxygen because of contact with the MnO₂ catalyst 260.

The oxygen-generating composition 190, catalyst 260, and the water 175can be provided in any amounts suitable for initiating and maintainingthe oxygen generation reaction.

As noted earlier, there are situations where individuals are inrespiratory distress and need oxygen immediately. The present inventionaddresses that problem by providing contaminant-free oxygen within ashort time after the portable oxygen generation device described andclaimed here is actuated. In operation, oxygen is generated by using theportable chemical oxygen generator of the present invention in proximitywith the individual needing oxygen, so that once flowing a patient maybegin to breathe the oxygen via a mask or nasal cannula in fluidcommunication with the device.

The oxygen generation process takes place in the device of the presentinvention as follows. The process begins by placing the device on agenerally-horizontal surface. The user first removes a restraint 189that is placed on the actuation means and then rotates the actuationmeans (e.g., a handle 180) approximately 270°, the same arcuate path asmoving a clock's minute hand from the 12:00 to 9:00 position (see FIGS.6A and 6B). According to an alternative embodiment, the user rotates theactuation means (e.g., a handle 180) approximately 90°, the same arcuatepath as moving a clock's minute hand from the 3:00 to 6:00 position. Therestraint 189 prevents accidental actuation of the handle 180 and alertsa user when the device has previously been activated (and thus renderedunusable). The handle 180 is connected with valve assembly 200, which isunderneath the lid 120. Before actuation the valve assembly 200 issealed off from, but adjacent, several other sealed compartments,namely, the oxygen-accumulation chamber 122 underneath the lid 120, thewater reservoir 170, and the housing 140 beneath the support plate 160.

Actuation of the handle 180 causes the downward displacement of thevalve 220 and cap 250 with respect to valve body 210, as shown in FIG.3C. This displacement disengages o-rings in slots 284, 286, 288, and 292on valve 220 away from the surface of valve body 210. Water 175 fromreservoir 170 flows through openings 218 and 219 through the holdingchamber 265, taking catalyst 260 along as it flows downward into housing140. This arrangement assures that the catalyst 260 is delivered intothe reaction mixture. In one embodiment, shown in FIG. 3E, afteractuation the valve 220 travels down the threading of screw 230 and mayseparate from the screw. If such separation occurs, valve 220 and cap250 drop from the interior of valve body 210 into the housing 140, alongwith water 175 and catalyst 260. One additional benefit is that thisassures the likelihood that all of catalyst 260 is present with thewater 175 and oxygen-generating mixture 190 to optimize the reaction inhousing 140.

The previously described oxygen generation chemical reaction thenoccurs. According to an embodiment illustrated by FIG. 5A, generatedoxygen and water vapor flow upward through the valve assembly 200, outthrough holes 211 and 213 of the valve housing 210, and into the spacebetween the top surface of the reservoir 170 and the bottom surface ofthe membrane 171. Oxygen flows through the liquid-impermeable,gas-permeable membrane 171 into the collection chamber 122 and then outof the device 100 via oxygen port 125. Membrane 171 serves to preventthe reaction mixture from passing into the collection chamber 122, andfurther prevents liquid from exiting the device.

According to an embodiment illustrated by FIG. 5B, generated oxygen andwater vapor flow upward through the center valve assembly 200′, outthrough holes 211′ and 213′ of the valve housing 210, and into the spacebetween the top surface of the reservoir 170 and the bottom surface ofthe membrane 171. Oxygen flows through the liquid-impermeable,gas-permeable membrane 171 into the collection chamber 122 and then outof the device 100 via oxygen port 125. Membrane 171 serves to preventthe reaction mixture from passing into the collection chamber 122, andfurther prevents liquid from exiting the device.

According to these embodiments, once device 100 has been actuated, valveassembly 200′ provides a separate pathway that allows oxygen generatedby the reaction to flow upward, but not along the same pathway thatwater 175 and catalyst 265 travel when flowing into housing 140, asillustrated by FIG. 5B. Generated oxygen enters the valve assembly 200′at the bottom through hole 251′. It then passes through central bore233′ of screw 230′ and exits through now-aligned openings 234′/213′ and235′/211′ before flowing into the space between the top surface of thereservoir 170 and the bottom surface of the membrane 171, as illustratedby FIG. 5B. The generated oxygen then continues on this gas flow pathwaythrough the liquid-impermeable, gas-permeable membrane 171 into thecollection chamber 122 and then out of the device 100 via oxygen port125.

As discussed above, when device 100 is in the actuated state, water 175and catalyst 265 flow out along the sides of valve 200′ assembly, whilegenerated oxygen enters the valve assembly 200′ through hole 251′. Byhaving the separate gas flow pathway, oxygen initially generated at thebeginning of the oxygen-generating reaction does not compete with theflow of water 175 and catalyst 265, resulting in economies of time andefficiency not only for oxygen reaching the oxygen port 125, but alsofor water and catalyst being delivered to housing 140 to expedite theoxygen-generation process.

The generated oxygen that flows out of the device 100 at oxygen port 125includes water vapor and may well be above ambient temperature. Toreduce the condensation that may exit the tubing into the mask or nasalcannula, which may be unpleasant for a patient, a water trap 300 forcollecting condensate is shown in FIG. 8. The water trap 300 isinterposed between the outlet port 125 (see FIG. 1) and the mask ornasal cannula (not shown). In one embodiment, the water trap 300 isformed of heat-sealable and gas-tight flexible barrier materials, e.g.,CADPAK HD100 packaging material by Cadillac Products Packaging Co. ofTroy, Mich. According to an embodiment of the invention, the materiallikewise has high thermal conductivity. The water trap 300 has an inlet305 connected with oxygen port 125 and an outlet 310 connected with atube that is connected on its other end with the mask or cannula. Thewater trap 300 simultaneously provides a pathway for the generatedoxygen while trapping condensation.

According to one embodiment, the water trap 300 has a series of verticalinternal barriers 315 that are staggered on opposite sides, with eachsuch barrier projecting more than half the distance from one interiorsidewall 320 of the water trap 305 to the other interior sidewall 321.This configuration ensures that oxygen passing through the trap travelsa path 325 that if laid out on a straight line would be longer than thelength of the water trap 300 itself. This elongated path 325 has theadded benefit of allowing for the collection of more condensate than thestraight path alone. In addition, the longer flow path enhances coolingthe generated gas closer to ambient temperature, thus increasing theamount of moisture condensed from the gas stream and reducing unwantedcondensation in the tube leading to the mask or cannula. In oneembodiment of the invention, the water trap 300 is generally rectangularin shape. In the embodiment shown in FIG. 8, the water trap 300 has aninlet 305 on one end and an outlet 310 on the other end. In anotherembodiment, shown in FIG. 9, the water trap 350 has an inlet 355 and anoutlet 360 on the same side, with an internal barrier 366 that runsgenerally parallel to the sidewalls 370, 371 but closer to sidewall 371.The internal barriers 365 are staggered between interior sidewall 370and internal barrier 366, which runs generally perpendicular to internalbarrier 365. In this embodiment, the oxygen generated enters from inlet355 and travels through the water tap 350 along flow path 375, whichruns the length of internal barrier 366 before traveling through thearea defined by staggered internal barriers 365 and eventually exitingthe water trap 350 at outlet 360. This longer flow path allows for morecondensation to be captured.

According to one embodiment, a first length of tubing extends from thedevice's oxygen port 125 to inlet 305 of water trap 300 and a secondlength of tubing extends from outlet 310 to a mask or cannula. The firstlength of tubing may be long enough that when the device is used thewater trap 300 is positioned away from the housing 140 so that it is notheated by the oxygen-generating reaction.

For access and use by a patient needing oxygen, the device 100 of thepresent invention may be stored by itself (without a tube, facemask/nasal cannula, and/or water trap pre-connected, but in closeproximity). The device 100 may also be stored with a tube and facemask/nasal cannula, the tube preferably being pre-connected with oxygenport 125. In another embodiment, the device 100 may have two tubes, thefirst tube being pre-connected with oxygen port 125 on the first tube'sproximal end and with water trap inlet 305 on the first tube's distalend and the second tube being pre-connected with water trap outlet 310on the second tube's proximal end and with the face mask/nasal cannulaon the second tube's distal end.

According to embodiments, device 100 includes compartment 110 forstoring the face mask/nasal cannula and associated hosing, asillustrated by FIG. 17. According to these embodiments, compartment 110is releasably attached to outer layer 147 of device 100 near oxygen port125. Compartment 110 is sized and shaped to store and protect the facemask/nasal cannula and hosing prior to actuation, while also making theface mask/nasal cannula and hosing quickly and easily accessible.

According to a preferred embodiment, the periphery of compartment 110includes attachment element, e.g., tabs, protrusions, or the like (notshown), that engage with corresponding apertures in outer layer 147 (notshown).

Compartment 110 is further secured to device 100 by restraint 189.According to an embodiment, restraint 189 is a tape attached across bothhandle 180 (see FIG. 6A) and one side of compartment 110 (see FIG. 6C).The removal of restraint 189 from device 100 results in disengaging atleast some of the tabs or protrusions of compartment 110 from outerlayer 147, thus freeing the face mask/nasal cannula and associatedhosing for post-actuation use. For example, according to preferredembodiments, the tabs or protrusions of compartment 110 and thecorresponding apertures of outer layer 147 are designed so that removingrestraint 189 disengages at least those tabs or protrusions from outerlayer 147 necessary for compartment 110 to swing open. According to oneembodiment, restraint 189, in the form of tape, is attached across atleast a portion of the outer side of compartment 110 and continues overthe edge of compartment 110 (e.g., is folded) and is attached to atleast a portion of the inner side of compartment 110 (not shown).Accordingly, in this embodiment, when the restraint 189 is pulled to bereleased from device 100, restraint 189 will remain attached to aportion of compartment 110. This, in turn, allows for quick-and-easyaccess to the face mask/nasal cannula and associated hosing.

An oxygen generator according to an embodiment of the present inventionmay be assembled as follows. Valve housing 210 is connected with areservoir 170 by heat sealing flanges 214 and 216 to upper and lowersurfaces of the reservoir. Valve assembly 200 is then partiallyassembled as shown in FIG. 10 (with the valve assembly 200 inverted aswill be explained below).

As part of the assembly of valve 200, valve body 220 is inserted intovalve housing 210 so that the o-rings disposed in flanges 286 and 288engage the interior surfaces of the valve housing 210 as discussed abovewith regard to FIG. 3B. Screw 230 is threaded into valve body 210. Theo-rings in slots 280 and 284 engage interior surfaces of the valvehousing 210 and valve body 220, respectively. At this stage, cap 250 isseparate from valve body 220. Note that openings 228 and 229 in valvebody 220 (shown more clearly in FIG. 3A) are in fluid communication withopenings 218 and 219 of valve housing 210 and thus also in fluidcommunication with reservoir 170. Also, the interior of valve body 220is hollow so that opening 270 of valve body 220 is also in fluidcommunication with the reservoir 170 via openings 218, 219, 228, 229.Also, catalyst chamber 260 is partially formed above the o-ring in slot288. The catalyst chamber 260 is open at its upper end through theinterior of valve housing 210.

The reservoir 170 is then filled with a predetermined amount of aqueoussolution 175. The solution is introduced through opening 170 in valvebody 220 and flows through the interior of valve body 220 and throughopenings 218, 219, 228, 229 into reservoir 170. Catalyst 265 isdelivered to the partially formed catalyst chamber 260 through the openend of valve housing 210. Cap 250 is then inserted into the open ends ofvalve housing 210 and valve body 220. Snap engagements on posts 254 and256 engage edges of openings 228 and 229 to fix the cap 250 with respectto the valve body 220. O-rings in slots 290 and 292 on the cap 250sealingly engage with interior surfaces of the valve body 220 and valvehousing 210, respectively. As a result, the aqueous solution 175 isprevented from flowing through the valve 200 and the catalyst 265 issealed within the catalyst chamber 260, preventing any interaction ofthe solution 175 and catalyst 265 until the device is actuated. When thevalve assembly 200 and reservoir 170 are positioned right-side up, thevalve 200 is in the configuration shown in FIG. 3B.

The device is further assembled as follows. A predetermined amount ofthe oxygen-generating mixture 190 is placed on the bottom of housing140. As shown in the exploded view of FIG. 1, support plate 160 ispositioned in housing 140 and rests on the shelves 148 formed by theupper ends of ribs 146. Valve assembly 200 is inserted through a hole inthe center of the support plate 160 and tabs 215 on the lower portion ofvalve housing 210 engage with extensions 154 and 156 of valve supportassembly 144 by snapping into slots 153, as discussed with respect toFIG. 2A. According to an alternative embodiment, valve assembly 200′(not shown) is inserted through a hole in the center of the supportplate 160, and tabs 215 on the lower portion of valve housing 210′engage with extensions 154 and 156 of valve support assembly 144 bysliding into slots, as discussed with respect to FIGS. 11 and 12.

The edge of reservoir 170 is engaged with the rim of housing 140.According to one embodiment, as shown in FIG. 1, holes 137 along theedge of reservoir 170 are fitted over pins 139 along the rim of housing140. According to another embodiment, the edge of reservoir 170 is heatsealed to the rim of housing 140.

Lid 120 is fitted over the edge of housing 140 with the upper portion ofvalve 200 extending through opening 124 in lid 120. Nut 240 is threadedonto the top of valve assembly 200, securing valve assembly 200 to thelid 120. Because valve assembly 200 is fixed to the bottom 143 ofhousing 140 by the valve support 144 and to the lid 120 by nut 240, thevalve assembly 200 provides structural support to hold the lid 120against the housing 140. As a result, forces due to increased gaspressure will not cause the lid 120 to detach from housing 140 whenoxygen is generated. Handle 180 is then connected with screw 230 of thevalve assembly 200. A machine screw 188 is inserted through a hole inthe handle and secures the handle 180 to the valve assembly 200 to allowthe device to be actuated as described above. According to oneembodiment, a restraint 189 such as an adhesive label is applied to thehandle 180 and lid 120.

While this invention has been described in conjunction with the specificembodiments outlined above, it is evident that many alternatives,modifications, and variations will be apparent to those skilled in theart. Accordingly, the preferred embodiments of the invention as setforth above are intended to be illustrative, not limiting. Variouschanges may be made without departing from the spirit and scope of theinventions as defined in the following claims.

We claim:
 1. A chemical oxygen generator comprising: a housing; areaction chamber within the housing; a valve, a lower portion of thevalve in fluid communication with the reaction chamber; an internalchamber within the valve; a reservoir in fluid communication with anupper portion of the valve; and a valve actuator, wherein operation ofthe valve actuator creates: (1) a first fluid pathway from the reservoirthrough the internal chamber into the reaction chamber; and (2) a secondfluid pathway through an approximate center of the valve.